The present disclosure pertains to a sensor involving a visual color change due to the presence of an aqueous-based liquid. In particular, the disclosure relates to an a wetness sensor that communicates to a caregiver or user that a personal hygiene article is ready for changing.
Wetness sensing capability in an personal hygiene article, such as an absorbent article, has been a desirable and welcome feature. Disposable absorbent articles such as diapers, training pants, incontinence pads, and the like are highly absorbent and efficiently pull moisture away from the wearer, thereby reducing skin irritation caused by prolonged wetness exposure. However, because these articles are so absorbent, wearers may not realize they have urinated, particularly if they are inexperienced toddlers who may not recognize the meaning of body sensations associated with urination. Thus, the wearer may not recognize their urination control failure or be aware the article should be changed. Furthermore, caregivers may not recognize that the absorbent article requires changing.
Visual mechanisms have been employed to signal the presence of wetness in absorbent articles. There are a large number of wetness sensing technologies that currently exist including electronic-based wetness sensors, color-based wetness sensors, and enzyme-based wetness sensors. However, all those wetness sensing technologies are not ideal and have one or more limitations. For instance, the electronic based wetness sensors are generally too expensive to be disposable, while enzyme-based wetness sensors may have stability issues. Water-soluble dye-based wetness indicators experience dye leaching upon wetting and present blurred graphics.
Thus, a need exists for a wetness sensor that is cost effective, stable and capable of a wide variety of hue changes. A personal hygiene article, in particular an absorbent article, that incorporates such a sensor would be beneficial.